LJMAX

From FEFF

Advanced

LJMAX lj

This is an NRIXS option and will be ignored for any other type of spectroscopy. LJMAX influences all modules starting from xsph. This card specifies the number of terms included in
the calculation of the excitation matrix elements

Typically the value of angular momentum channels needed is dependent on the momentum transfer and energy transfer range that one is calculating. For typical XANES calculation one does not need lj > 10 and most often lj = 5 is sufficient. For EXAFS one needs more than for XANES. However, most often this parameter has to be determined on case-by-case basis. If this parameter is too large it can occasionally cause small errors. For lj > 25 the code starts to become unstable. Default value is lj = 1, approximately corresponding to the dipole selection rule.